Internal combustion engine and piston therefor



June 19, 1934. s. e. RUSSELL INTERNAL COMBUSTION ENGINE AND PISTON THEREFOR Filed April 12, 1933 2 Sheets-Sheet 1 m flHwflMwH n M ii 5 h 5 10!: 5 WW M x H M Z m 1 F I F IN]: M /o w o w 0 7 H m o p o o N 3 6 M 5 5 7 a:

7 e 19, 1934- 5. cs. RUSSELL 1,963,151

INTERNAL COMBUSTION ENGINE AND PISTON THEREFOR Filed April 12, 1933 2 Sheets-Sheet 2 A I 1 l INVENTOR 5002416/ 6 H1656 Patented June 19, 1934 PATENT OFFICE INTERNAL COMBUSTION ENGINE AND PISTON THEREFOR Samuel G. Russell, Kalamazoo, Mich., assignor of one-half to J. E. Porter, Muskegon Mich.

Application April 12, 1933, Serial No. 665,764

10 Claims.

i inder wall.

Third, to provide a structure of this type characterized by the following advantages: reduced friction and blow-by, improved oil control, long life under poor operating conditions, increased 5 power, elimination of piston slap, the ability to fit out-of-round cylinder bores, and the elimination of scoring of the piston and cylinders.

Fourth, to provide means in a structure of this character which permits the piston to expand or contract under varying temperatures without affecting the efiiciency of the piston or rings. a

Fifth, to provide a piston having the above desirable features and advantages, which is simple and economical in its parts and very eflicient in operation.

Objects relating to details and economies of my invention will appear from the description to follow. The invention is defined and pointed out in the claims.

A structure which is a preferred embodiment of my invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a fragmentary view partially in side elevation and partially in vertical section on line 11 of Fig. 2 of a piston embodying my invention. I

Fig. 2 is a transverse detail section.

Fig. 3 is a perspective view of one of the ring segments.

Fig. 4 is an enlarged fragmentary vertical section showing the position of the parts before upper part or head 3 of such diameter as will insure necessary clearance with the cylinder bore 4 at all operating temperatures. The lower part 5 or-main portion of the skirtof the piston is of a larger diameter, it being of such diameter as M to eliminate any possibility of this portion of the piston having insufiicient clearance under all operating conditions so that it floats freely or is not brought into close frictional contact with the walls when under greatest expansion. I have a not, however, in the accompanying drawings attempted to illustrate the exact proportions and clearance, and it will be understood that thes will vary for different materials. 1

The piston is provided with piston ring grooves 6 and 7 for the accommodation of relatively wide piston rings 8 and 9, these being of such width that they efiectively constitute bearing surfaces coacting with the walls of the cylinder. The grooves are provided with centrally disposed an- '7 nular lands or ribs 10 which provide annular groove-like recesses 11 at each side adapted to receive the inwardly extending annular flange portions 12 of the rings. These flange portions are formed by an internal annular groove in the 0 rings. The width of the ribs is sufiiciently in excess of the width of the grooves that the ring grooves are expanded. The force required to expand the rings has a tendency to distort the peripheral surface, causing it to present a slightly concave surface having raised edges 13 which permits the ring to seat properly in a short period of time. It will be understood that the curve is materially exaggerated in the drawings.

The width of the ribs 10 is sufiiciently wider than the internal annular groove in the ring to cause a substantial friction or pinch on the ribs 10, thus eliminating piston slap and also permitting the piston to expand or contract without danger of pinchingv or scoring in the cylinder bore.

This distortion of the ring is facilitated by the slots 14 through the face of the ring, the outer edges of the slots being in the planes of the walls of the groove of the ring. These slots are ar- 10 ranged instaggered and alternating relation as shown in the drawings.

The pressure required to expand the ring naturally exerts or causes friction between the sides of the grooves and the ribs, which resists the it tendency of the piston to rock in the cylinder by forces exerted against the piston head, at the same time establishing a very efiective seal eliminating the possibility of explosive gasses from the' combustion chamber getting between the i] ring and the bottom of the groove on their way from the combustion or compression chamber,

and also at the same time preventing the pas-' sage of oil from the base of the motor to the combustion or compression chamber by the same route.

" It will'be noted that by varying the length of slot 14 and the distance between each row of slots 14 I am enabled to control the longitudinal presssure exerted by the ring against the side of the rib 10.

The ribs have annular peripheral grooves 15 providing recesses or seats forthe corrugated blade springslfi which act to yieldingly support the rings in yielding contact with the cylinder wall and substantially support the piston relative thereto. The piston may have ports 17 connecting the bottoms of the grooves 15 with the interior of the piston so that any surplus of lubricant may pass through the slots 14 to the interior of the piston.

In operation, the parts coact to cause the piston to "float under all operating temperatures without excessive frictional contact with the cylinder wall, thus giving all the advantages of pistons formed out-of-round or having split skirts to accommodate expansion without the accompanying, disadvantages inherent to such pistons, and permitting the use of various alloys which have the advantage of lightness but'are open to the objection of excessive expansion.

The piston illustrated is provided with a piston ring groove 18 at its head end and a firing ring 19. A single ring is illustrated,.but it will be-un-.

derstood that a plurality of rings may be employed or rings of the oil circulating type may be employed at'this point or below the contracting ring.

The rings 6 and 'l are preferably made up of complementary sections or segments 20. The joints 21 and 22 between these segments are pref-r erably positioned in' the vertical plane passing through the axis of the wrist pin 23. I preferably "provide the rings with locating pins 24 so that their position relative to the wrist pin is maintained. The joint 21 is preferably a broken as distinguished from a cut joint as at 22.

The ring casting is preferably provided with an inner recess or notch 25 diametrically opposite the point at which the cut joint is'to be formed and when the hole 26 has been bored for the pin 24 the ring is weakened at this point to su'chan extent that it is easily broken, after the cut to form the joint 22 has been made, merely by pulling the.

ends apart, and'the break is in an approximately predetermined position. The advantage of this is that no stock is removed in forming the joint 21 and it isunnecessary to make allowances or tolerance for two outs, it being standard practice to make an allowance or tolerance for the single cut. Each of the ring segments is yieldinglysup-- ported by the spring 16.

The action of the spring against the ring tends to counteract the tendency of the ring to present If a concave surface to the cylinder wall so that the seating ridges 13 near the edges of the rings are relatively quickly worn away so that a. substantially flat bearing surface is presented to the cylinder wall. The springs are of sufficient tension to force the rings against the cylinder wall. The side friction of the ring segments, together with the springs, permits the piston to expand or contract .under varying temperatures and does not affect the efficiency of the piston or rings.- The piston is eflicient and has excellent oil control be- 1,'963,151 cause of the relatively long ring bearing surface joint.

with comparatively little or no piston contact with the cylinder wall. This considerably reduces friction. In addition to permitting the expansion and contraction of the piston, the springs underneath the rings act to eliminate piston slap and scoring of piston and cylinder walls.

It is not intended that the outer sides of the wide rings will contact the side surfaces of the piston grooves 6 and 7, in which case any blowby getting past the firing ring would eventually exert pressure against the inside surfaceof the angular flange portion 12 causing the'ring to exert additional pressure against the cylinder wall. This condition is more likely to exist when the motor is laboring hard or at high speeds and proves beneficial to the performance of the motor. The skirt of the piston itself is preferably turned .to the diameter of the cylinder bore less an amount that will insure normal piston clearance less such additional clearance as will insure the impossibility of insufficient piston clearance under the most unfavorable operating conditions.

If desired, oil controlrings may be used and the piston may be drilled for oil control as found necessary.

Among struction may be listedlow friction, substantial the advantages of my improved con- I elimination of blow-by, efficient oil control, freedom from carbon troubles, long life under poor operating conditions, more power, and the elimination of piston slap and piston scoring. In addition, my improved piston is simple in construction, economical to manufacture, and efilcient and efiective in operation.

Referring-to Figs. 6 to 8, inclusive, of the drawings, there is illustrated a modification wherein the expanding ring segments 30 have slots 31 disposed decidedly to one side of the center of the ring, the slots being arranged in staggered and alternating relation with respect to each other as described above connection with Figs. 1 to 5, inclusive. The ring segments have internal grooves 32 facing the external groove 33 in the ring recess 34. A corrugated spring 35 is seated in the grooves 32 and 33 and acts to urge the ring segments outwardly into engagement with the wall of the cylinder bore. The piston has wall ports 36 opening to the bottom of the groove 33. Otherwise, the structure is similar to that described abovein connection with Figs. 1 to 5.

The arrangement of the slots in the modification prevents the ring from bulging outwardly in the center due to the weakening of the ring and the radialthrust of thespring. Thus, the ring,

presents a fiat surface to the cylinder wall. The

ring is fit snugly between the upp r and lower 1. The combination with a cylinder, of apiston of such diameter that it has suflicient clearance to permit it to float within the cylinder under all adjacent the ends thereof provided with central [annular ribs of less depth than the grooves, said operating conditions and having annular grooves the grooves to the interior of the piston, said ribs being of outwardly 'tapered'cross section,

piston rings comprising complementary segments arranged-in said grooves and of such width as provide bearing surfaces for the piston coacting with the walls of the cylinder, said piston rings having internal annular grooves and a double series of slots extending therethrough and positioned with theouter walls of the slots in the planes of the outer walls of the grooves of the ring, the grooves of said rings being of slightly less width than the width of the ribs so that the walls of the grooves of the rings are spread when engaged with the ribs thereby curving the faces of the rings inwardly, positioning pins on said cylinder engaging the rings at joints thereof and so that their joints are in the central longitudinal plane of the piston through the axis of its wrist pin, and corrugated springs arranged in said grooves in said ribs to yieldingly support said rings.

2. The combination with a cylinder, of a piston of such diameter that it has suflicient clearance to permit it to float within the cylinder under all operating conditions and having annular grooves adjacent the ends thereof provided with central annular ribs of less depth than the grooves, said ribs being of outwardly tapered cross section, piston rings comprising complementary segments arranged in said grooves and .of such width as to provide bearing surfaces for the piston coacting with the walls of the cylinder, said piston rings having internal annular grooves, the grooves of said ring, being of slightly less width than the width of the ribs so that the walls of the grooves of the rings are spread when engaged with the ribs thereby curving the faces of the rings inwardly, positioning pins on said cylinder engaging the rings at joints thereof and so that their joints are in the central longitudinal plane of the piston through the axis of its wrist pin, and corrugated springs arranged to yieldingly support said rings.

3. The combination with a cylinder, of a piston of such diameter that it has sufiicient clearance to permit it to float within the cylinder under all operating conditions and having annular grooves adjacent the ends thereof provided with central annular ribs of less depth than the grooves, piston rings comprising complementary segments arranged in said grooves and of such width as to provide bearing surfaces for the piston coacting with the walls of the cylinder, said piston rings having internal annular grooves, positioning pins on said cylinder engaging the rings at joints thereof and so that their joints are in the central longitudinal plane of the piston through the axis of its wrist pin, and corrugated spring arranged to yieldingly support said rings.

4. The combination with a cylinder, of a piston of such diameter that it has sufiicient clearance to permit it to float within the cylinder under all operating conditions and having annular grooves adjacent the ends thereof provided with central annular ribs of less depth than the grooves, said ribs having peripheral grooves, said of piston having a plurality of bores leading from the bottoms of the grooves to the interior of the piston, said ribs being of outwardly tapered cross section, piston rings arranged in said grooves and of such width as to provide bearing surfaces for the piston coacting with the walls of the cylinder, said piston rings having internal annular grooves and a double series of slots extending therethrough and positioned with the outer walls of the slots in the planes of the outer walls of the grooves of the ring, the grooves of said rings being of slightly less width than the width of the ribs so that the walls of the grooves of the rings are spread when engaged with the ribs thereby curving the faces of the rings inwardly, and expansion springs arranged in said grooves in said ribs to yieldingly support said rings.

5. The combination with a cylinder, of a piston of such-diameter that it has suflicient clearance to permit it to float within the cylinder under all operating conditions and having annular grooves adjacent the ends thereof provided with central annular ribs of less depth than the grooves, said ribs being of outwardly tapered cross section, piston rings arranged in said grooves and of such width as to provide bearing surfaces for the piston coacting with the walls of the cylinder, said piston rings having internal annular grooves, the grooves of said rings being of slightly less width than the width of the ribs so that the walls of thegrooves of the rings are spread when engaged with the ribs thereby curving the faces of the rings inwardly, and expansion springs arranged to yieldingly support said rings.

6. A piston and ring assembly for internalcombustion engines comprising in combination a piston having a skirt the diameter of which is less than the diameter of the cylinder bore by an amount equal to the maximum expansion of the piston metal plus suificient additional clearance to insure afree operating piston under extreme conditions, annular ring grooves provided with annular center lands having annular spring recesses and ports opening to said recesses, rings disposed in said ring grooves and having annular flanges disposed in the recesses above and below said lands and a pair of series of slots adjacent the flanges, the width of the lands being slightly'greater than the width of the distance between said flanges whereby the outer walls of the rings are concaved to provide wear seating ridges, and springs disposed in said spring recesses and acting to center the piston in the cylinder, allow for expansion of the piston and eliminatepiston slap and scoring of the cylinder bore and piston.

7. A piston and ring assembly for internal combustion engines comprising in combination a piston having askirt the diameter of which is less than the diameter of the cylinder bore by an amount equal to .the maxium expansion of the piston metal plus suflicient additional clearance to insure a free operating piston under extreme conditions, an annular ring groove provided with an annular center land having an annular spring recess and ports opening to said recess, a ring disposed in said ring'groove and having annular flanges disposed in the recesses above and below said land and a pair of series of slots adjacent the flanges, the width of the land being slightly greater than the'width of the distance between said flanges whereby the outer wall of the ring is concaved to provide wear seating ridges, and a spring disposed in said spring recess and acting to center the piston in the cylinder, allow for expansion of the piston and eliminate piston slap and scoring of the cylinder bore and piston.

8. A piston comprising a skirt having an'annular ring groove provided with a central annular rib of less depth [than the groove, the rib having an annular peripheral groove, a piston ring coml0. A piston and ring assembly comprising. a

piston having a land, and'a ring having 'fla fi engaging said land to concave the face of the ring, the width of the land being greater. than the distance between the flanges for this purpose and to insure the clamping of the land by the flanges.

SAMUEL G. RUSSELL. 

